SIO: Savannah - Post-Tropical

[TorSkk]

99S INVEST 190307 1200 13.0S 113.0E SHEM 15 0

[TorSkk]

A tropical low (17U) is forecast to form south of Bali today (Thursday). If it does form, it is expected to track in a west to southwesterly direction and gradually develop, and pass close to Christmas Island late Sunday or during Monday. There is a Low (less than 20%) chance of this system developing into a tropical cyclone on Saturday and Sunday, increasing to a Moderate chance on Monday.


Likelihood of this system being a tropical cyclone in the Western Region on:

Friday:Very Low
Saturday:Low
Sunday:Low

[TyphoonNara]

AN AREA OF CONVECTION (INVEST 99S) HAS PERSISTED NEAR
10.7S 114.5E, APPROXIMATELY 560 NM EAST-SOUTHEAST OF JAKARTA.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 080106Z GMI 89GHZ
MICROWAVE IMAGE SHOW A PERSISTENT BALL OF DEEP CONVECTION OVER AND
OBSCURING THE LLC. 99S IS CURRENTLY IN A VERY FAVORABLE ENVIRONMENT
WITH EXCELLENT POLEWARD OUTFLOW, VERY LOW (5 TO 10 KNOTS) VWS, AND
VERY WARM (29 TO 30 CELSIUS) SST. GLOBAL MODELS ARE IN GOOD
AGREEMENT THAT 99S WILL CONTINUE TO TRACK WESTWARD BEFORE BEGINNING
TO RECURVE SOUTHWEST, ALL THE WHILE INTENSIFYING. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.

[TorSkk]

Indonesian Agency for Meteorology Climatology and Geophysics

Jakarta Tropical Cyclone Warning Centre (TCWC)



TROPICAL CYCLONE OUTLOOK



Tropical Cyclone Outlook for Southern Indonesia area

Issued Friday, March 08th 2019 09.00 Western Indonesia Time



Current Tropical Cyclone in the Southern Indonesia area:

None.



Tropical cyclone development possibility:

Suspect area with minimum pressure 1008 mb is observed in Indian Ocean near 11 S 114 E, south of East Java , and moving southwestward.

Weak Low 1009 mb is observed in Timor Sea near 9 S 129 E, east of Kupang and moving westward to northwestward.



Possibility to develop into tropical cyclone:

Saturday (tomorrow) : very small possibility

Sunday (tomorrow +1): very small possibility

Monday (tomorrow +2) : small possibility



Note:

Small possibility means possibility for the suspect area to develop into tropical cyclone is less than 10%.

Medium possibility means possibility for the suspect area to develop into tropical cyclone is about 20%-40%.

Large possibility means possibility for the suspect area to develop into tropical cyclone is more than 50%.



Southern Indonesia area is area within equator to 11 S and 90 to 141

[TorSkk]

A tropical low (17U) was located near 11.6S 114.1E at 11am WST Friday, about 350km SSW of Denpasar (Bali). It is expected to track in a west to southwesterly direction and gradually develop, and may pass close to Christmas Island late Sunday or during Monday, and close to the Cocos (Keeling) Islands during Tuesday or Wednesday. There is a Low (less than 20%) chance of this system developing into a tropical cyclone on Saturday and Sunday, increasing to a Moderate chance on Monday.


Likelihood of this system being a tropical cyclone in the Western Region on:

Saturday:Low
Sunday:Low
Monday:Moderate

[TorSkk]

THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED
NEAR 12.1S 113.1E, IS NOW LOCATED NEAR 12.5S 113.3E, APPROXIMATELY
537 NM SOUTHEAST OF JAKARTA, INDONESIA. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY AND A 091414Z MHS METOP-A 89GHZ PARTIAL IMAGE
DEPICT A BROAD, WEAKLY DEFINED LOW LEVEL CIRCULATION (LLC) WITH A
SMALL AREA OF FLARING CONVECTION IN THE WESTERN PERIPHERY. A 091416Z
ASCAT METOP-A PASS DEPICTS AN ELONGATED CIRCULATION WITH 20 KNOT
WINDS WRAPPING INTO IT FROM THE SOUTH. UPPER LEVEL ANALYSIS SHOWS
THAT THE SYSTEM IS LOCATED ON THE BORDER OF MODERATE TO HIGH (20-30
KT) VERTICAL WIND SHEAR WITH GOOD POLEWARD OUTFLOW. WARM SEA SURFACE
TEMPERATURES (29-30 CELSIUS) REMAIN CONDUCIVE FOR FUTURE
DEVELOPMENT. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT 99S WILL
TRACK WEST OVER THE NEXT 48-72 HOURS, BUT VARY ON TIMING AND
INTENSITY OF DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[TorSkk]

Tropical Cyclone Outlook for the Western Region

Issued at 3:45 pm WST on Monday 11 March 2019


Potential Cyclones:

A weak tropical low (17U) was located near 10.8S 105.1E at 2pm WST Monday, which is about 75 km west southwest of Christmas Island. It is forecast to continue moving west which takes it further away from Christmas Island. Later Tuesday it is forecast to take a southwesterly track, which would see it pass to the southeast of Cocos Island on Thursday. The risk of the system being a tropical cyclone increases over the new few days.


Likelihood of this system being a tropical cyclone in the Western Region on:

Tuesday: Low
Wednesday: Low
Thursday: Moderate

[TorSkk]

A weak tropical low (17U) was located near 8.9S 100.2E at 1pm WST Tuesday, which is about 600 km west northwest of Christmas Island and about 500km northeast of Cocos (Keeling) Islands. It is forecast to take a south to southwesterly track from Wednesday, which would see it pass to the east of Cocos (Keeling) Islands later on Wednesday or during Thursday. It is unlikely to have a significant wind impact on Cocos (Keeling) Islands, but shower and thunderstorm activity may increase on Thursday if the system passes close by. It is only a Low chance of developing into a tropical cyclone in the next three days.

[TorSkk]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 10.4S
104.1E, IS NOW LOCATED NEAR 8.9S 99.1E, APPROXIMATELY 230 NM
NORTHEAST OF COCOS ISLAND. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS FLARING DEEP CONVECTION OVER THE LOW LEVEL CIRCULATION
(LLC). A 121454Z MHS METOP-A 89GHZ MICROWAVE IMAGE SHOWS A SMALL
POCKET OF DEEP CONVECTION BEGINNING TO WRAP INTO THE LLC. 99S IS
CURRENTLY IN A FAVORABLE ENVIRONMENT WITH MODERATE EQUATORWARD
OUTFLOW, LOW (10 TO 15 KNOT) VERTICAL WIND SHEAR (VWS), AND WARM
(28 - 30 CELSIUS) SEA SURFACE TEMPERATURES (SST). GLOBAL MODELS ARE
IN GOOD AGREEMENT THAT 99S WILL TRACK SOUTHWARD WITH MINIMAL TO NO
INTENSIFICATION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[TyphoonNara]

[TyphoonNara]

TPXS12 PGTW 150915

A. TROPICAL CYCLONE 19S (SAVANNAH)

B. 15/0850Z

C. 14.11S

D. 94.89E

E. FIVE/HMWRI8

F. T3.0/3.0/D0.5/24HRS STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN WRAPS .60 ON LOG10 SPIRAL
YIELDING A DT OF 3.0. MET/PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


MARTIN

[TyphoonNara]

TPXS12 PGTW 170900

A. TROPICAL CYCLONE 19S (SAVANNAH)

B. 17/0830Z

C. 16.25S

D. 90.92E

E. THREE/MET8

F. T5.5/5.5/D1.5/24HRS STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 11A/PBO RAGGED EYE/ANMTN. LLCC EMBEDDED IN B YIELDS
A DT OF 5.0. MET AND PT BOTH YIELD A 5.5. DBO PT.

I. ADDITIONAL POSITIONS: NONE


MILAM

[TyphoonNara]

Now a Cat 3.

19S SAVANNAH
As of 06:00 UTC Mar 17, 2019:

Location: 16.3°S 91.0°E
Maximum Winds: 100 kt
Minimum Central Pressure: 948 mb

[TyphoonNara]

JTWC thinks the system has peaked.